This invention relates, in general to custom molded thoracic lumbar sacral orthosis (orthopedic braces), and more particularly, relates to methods and apparatus for formation of a custom molded impression of a patient""s torso which can subsequently be used to form an immobilization cast or torso brace.
Considerable effort has been directed toward the formation of orthopedic immobilizing casts or braces for various portions of patients"" anatomies, most usually limbs. To the extent that casts or braces are formed for limbs, or even for a patient""s torso, the cast and/or brace must be sufficiently rigid to support and/or immobilize the portion of the patient to which the cast is applied. This, in turn, usually requires that casts or braces be formed of a multiplicity of layers of material to provide the necessary strength and rigidity for immobilization or substantial weight support.
Typical of the prior art multi-layered casting systems are the orthopedic casts shown in U.S. Pat. Nos. 5,514,080; 4,683,877; 4,129,127; 4,019,506; and 3,656,475. Since these systems employ multiple layers and various combinations of hardening materials, they are tedious and difficult to form on the patient in order to achieve the highly desirable custom fit. Such custom casting, it will be understood, is often undertaken when the patient is in pain or experiencing considerable discomfort, making the construction of a cast in situ a disagreeable experience. Morever, part of a casting process often requires that a patient be held or maintained in a desired position during casting so that the eventual cast will support the patient as needed.
As the casting time becomes longer due to the complexity of forming a cast with sufficient rigidity to support the patient, it is more difficult to maintain the desired patient orientation or positioning.
Since in situ casting is often accomplished using resins which produce considerable heat during rigidification, another problem is providing sufficient thermal insulation between the patient and the various casting layers, which can contain a substantial volume of resin. Many casting resins experience exothermic curing. The thermal insulation required to withstand exothermic resin curing again makes the process of in situ casting more complex and tedious, as well as interposing layers between the patient and the eventual rigid cast which can affect cast fit.
Accordingly, it is an object of the present invention to provide a custom molded orthopedic impression shirt that can be used to mold an impression of a patient""s torso from which custom, rigid, immobilizing or supporting thoracic lumbar sacral orthosis can be made in the laboratory.
A further object of the present invention is to provide a molded orthopedic impression shirt, and kit for forming the same, which can be used to form an impression of a patient""s torso in a relatively short period of time.
A further object of the present invention is to provide a kit for and a method of forming, a custom molded orthopedic impression shirt that requires the use of minimal resin and the generation of minimal heat during the in situ molding process.
A further object of the present invention is to provide a method of forming a custom molded orthopedic impression shirt, and kit therefore which can be easily used by medical technicians with minimal training.
Still a further object of the present invention is to provide a custom molded orthopedic impression shirt and method which are suitable for scanning to enable the subsequent formation of an immobilizing or weight supporting thoracic lumbar sacral orthosis in a laboratory setting.
Still a further object of the present invention is to provide a custom molded orthopedic impression shirt, and method for formation of the same which can act as a base for a multi-layered immobilization or support cast or brace that is formed in the laboratory after the impression is taken.
The custom molded orthopedic impression shirt, method and kit of the present invention have other objects and features of advantage which will become apparent from, or are set forth in more detail in, the accompanying drawing and the following description of the Best Mode of Carrying out the Invention.
The method of forming a custom molded orthopedic impression shirt of the present invention comprises, briefly, the step of mounting a thin, flexible, resin-impervious release shirt or layer on the patient""s torso. Alternatively, the release shirt or layer may be mounted under or over a thin elastic, thermally insulating, shirt or layer which is mounted on the patient""s body. The method further includes the steps of mounting a resin-impregnated, thin, elastic, fabric impression shirt on the patient""s torso over substantially the entire release shirt and thermal insulating layer, if there is one. The fabric impression shirt has sufficient elasticity to conform the release shirt, the insulating shirt and the impression shirt itself to the patient""s torso. Finally, the method includes the steps of hardening the resin in the insulating shirt while mounted on the patient""s torso and removing the hardened impression shirt from the patient""s torso.
The present method further preferably includes the step of removing the hardened impression shirt by cutting the hardened impression shirt and release shirt and insulating fabric shirt along a side of the impression shirt and resiliently outwardly displacing the cut hardened impression shirt to enable removal from the patient""s torso. Finally, the method may include the steps of scanning the hardened impression shirt to obtain digital data corresponding to the shape of the impression shirt, and making a thoracic lumbar sacral orthosis based upon the scanned digital data. In an alternative aspect of the method of the present invention, the hardened impression shirt is used as a base, when removed from the patient, to enable formation of the orthosis over the impression shirt, either by casting the orthosis on a positive made from the impression shirt, or layering reinforcing materials over the impression shirt.
In another aspect of the present invention a kit for forming a custom molded orthopedic impression shirt is provided which comprises, briefly, a fabric impression shirt having a configuration substantially covering the torso of a patient and having sufficient elasticity and being sufficiently thin to enable formation of a shell conforming to the patient""s torso which is suitable for scanning, casting or reinforcing to manufacture a thoracic lumbar sacral orthosis once the impression shirt is removed from the patient""s torso. The kit also includes a quantity of curable resin, preferably impregnated in the impression shirt, sufficient to rigidify the impression shirt.